A boy rollerblades in front of the Winter Palace, the main building of Russia's famed Hermitage Museum. AP Photo/Dmitry Lovetsky.

ST. PETERSBURG (AFP).- Russia's renowned Hermitage museum warned of a return to Soviet-era repression of artists after local prosecutors said they were checking one of its exhibits for extremism.

The Saint Petersburg museum came under fire last week for hosting an exhibition by Britain's Jake and Dinos Chapman, visual artists known for their epic installations of little figurines in violent scenes.

The city's prosecutor's office said it was checking for "possible violations" by the organisers of their Hermitage show "End of Fun" after "numerous complaints from citizens."

"According to the complaints, the said show insults the feelings of Orthodox believers... and is directed at inciting hatred," the prosecutors said on their official website, referring to the criminal offence described in Russia's so-called "extremism" law.

The exhibit opened in October and runs until January 13.

It is a three-dimensional "landscape of hell in which the figures ceaselessly kill one another with diabolical cruelty," arranged in glass cases, according to the exhibit description. Some of the scenes show crucifixion.

The show's genre is meant to hark back to artists like Francisco Goya and Hieronimus Bosch and "cure society of that cruelty." It runs simultaneously with an exhibit of Goya's engravings.

Hermitage director Mikhail Piotrovsky praised the exhibit and denounced the "flourishing of a culture of informants in our society."

He compared it with the repressions of the Soviet era, specifically with complaints against poetry of Nobel laureate Joseph Brodsky, who was denounced as anti-Soviet, convicted of "social parasitism", and eventually driven to exile.

"We all remember the role of "society" in repressions," Piotrovsky wrote in a statement on the museum's website.

"Museums showing recognised master artists should not be afraid that anyone can set the prosecutors on them."

He added that letters sent by concerned citizens are all identical in wording and were apparently a concerted effort.

"A museum is an institution with a right to decide what is art and what should be exhibited," Piotrovsky said, adding that he has asked the prosecutor to look into the identical letters and defend the museum's dignity.

In a comment emailed to AFP Monday, Jake and Dinos Chapman offered a tongue-in-cheek apology and said they will never come to Russia again.

"We are extremely sorry to hear that some viewers of the End of Fun at the Hermitage were extremely upset," the statement said.

"We hope that the state prosecutor appointed to investigate accusations of extremism can accept our extreme apologies.

"P.S. Note to selves: remember, forget Russia."

The Hermitage press-service told AFP Monday that there are no plans to close the exhibition early.

Authorities in St. Petersburg, often referred to as Russia's culture capital, recently faced a series of accusations of artistic censorship.

In October, a modern art exhibit which included religious icons and sculptures was cancelled after Orthodox conservatives denounced it as anti-religious.